The manager is a new daemon which requires new CephX capabilities. If you upgrade
a cluster from an old version of Ceph, or use the default install/deploy tools,
your admin client should get this capability automatically. If you use tooling from
elsewhere, you may get EACCES errors when invoking certain ceph cluster commands.
To fix that, add a “mgr allow *” stanza to your client’s cephx capabilities by
Modifying User Capabilities.

Use the command cephmgrmodulels to see which modules are
available, and which are currently enabled. Enable or disable modules
using the commands cephmgrmoduleenable<module> and
cephmgrmoduledisable<module> respectively.

If a module is enabled then the active ceph-mgr daemon will load
and execute it. In the case of modules that provide a service,
such as an HTTP server, the module may publish its address when it
is loaded. To see the addresses of such modules, use the command
cephmgrservices.

Some modules may also implement a special standby mode which runs on
standby ceph-mgr daemons as well as the active daemon. This enables
modules that provide services to redirect their clients to the active
daemon, if the client tries to connect to a standby.

Consult the documentation pages for individual manager modules for more
information about what functionality each module provides.